U.S. patent number 10,651,066 [Application Number 15/879,651] was granted by the patent office on 2020-05-12 for metrology method in wafer transportation.
This patent grant is currently assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD.. The grantee listed for this patent is Taiwan Semiconductor Manufacturing Co., Ltd.. Invention is credited to Yen-Yu Chen, Yi-Ming Dai, Powen Huang, Chun-Chih Lin, Yao-Yuan Shang, Kuo-Shu Tseng.
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United States Patent |
10,651,066 |
Huang , et al. |
May 12, 2020 |
Metrology method in wafer transportation
Abstract
A method for fault detection in a fabrication facility is
provided. The method includes moving a wafer carrier using a
transportation apparatus. The method further includes measuring an
environmental condition within the wafer carrier or around the
wafer carrier using a metrology tool positioned on the wafer
carrier during the movement of the wafer carrier. The method also
includes issuing a warning when the detected environmental
condition is outside a range of acceptable values.
Inventors: |
Huang; Powen (Taichung,
TW), Shang; Yao-Yuan (Taichung, TW), Tseng;
Kuo-Shu (New Taipei, TW), Chen; Yen-Yu (Taichung,
TW), Lin; Chun-Chih (Taipei, TW), Dai;
Yi-Ming (Hsinchu, TW) |
Applicant: |
Name |
City |
State |
Country |
Type |
Taiwan Semiconductor Manufacturing Co., Ltd. |
Hsinchu |
N/A |
TW |
|
|
Assignee: |
TAIWAN SEMICONDUCTOR MANUFACTURING
CO., LTD. (Hsinchu, TW)
|
Family
ID: |
66632690 |
Appl.
No.: |
15/879,651 |
Filed: |
January 25, 2018 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20190164792 A1 |
May 30, 2019 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62590405 |
Nov 24, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01D
5/00 (20130101); H01L 21/67778 (20130101); G01D
7/00 (20130101); H01L 21/67393 (20130101); H01L
21/67733 (20130101); H01L 21/67288 (20130101); H01L
21/67276 (20130101); H01L 21/02079 (20130101); H01L
21/6773 (20130101); H01L 21/67389 (20130101); B08B
3/04 (20130101) |
Current International
Class: |
H01L
21/67 (20060101); H01L 21/677 (20060101); H01L
21/673 (20060101); H01L 21/02 (20060101); G01D
7/00 (20060101); G01D 5/00 (20060101); B08B
3/04 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lin; Jason
Attorney, Agent or Firm: McClure, Qualey & Rodack,
LLP
Parent Case Text
PRIORITY CLAIM AND CROSS-REFERENCE
This application claims the benefit of U.S. Provisional Application
No. 62/590,405, filed on Nov. 24, 2017, the entirety of which is
incorporated by reference herein.
Claims
What is claimed is:
1. A method for fault detection in a fabrication facility,
comprising: moving a wafer carrier using a transportation
apparatus, wherein the transportation apparatus moves the wafer
carrier along a predetermined path multiple times; collecting data
associated with an environmental condition within the wafer carrier
or around the wafer carrier using a metrology tool positioned on
the wafer carrier on the predetermined path in a previous movement
of the transportation apparatus; storing data associated with the
environmental condition in the previous movement of the
transportation apparatus in an archive database; measuring the
environmental condition within the wafer carrier or around the
wafer carrier using the metrology tool during the movement of the
wafer carrier; and issuing a warning when the measured
environmental condition is outside a range of acceptable values,
wherein the range of acceptable values is derived from the archive
database.
2. The method as claimed in claim 1, wherein when the warning is
issued according to the environmental condition measured within the
wafer carrier and when a wafer is positioned in the wafer carrier,
the method further comprises: transferring the wafer carrier to a
rework station; unloading the wafer from the wafer carrier to the
rework station; and removing a material layer over the wafer.
3. The method as claimed in claim 1, wherein when the warning is
issued according to the environmental condition measured around the
wafer carrier, the method further comprises: stopping an operation
of a fabrication tool.
4. The method as claimed in claim 1, wherein the range of
acceptable values is determined by a location where the wafer
carrier is located.
5. The method as claimed in claim 1, further comprising:
transmitting a data associated with the environmental condition to
a fault detection and classification system via an interface device
that is positioned at the transportation apparatus.
6. The method as claimed in claim 1, further comprising: placing
the wafer carrier on a load port of a processing tool; and
transmitting a data associated with the environmental condition to
a fault detection and classification system via an interface device
that is positioned at the load port.
7. The method as claimed in claim 1, further comprising: storing
the wafer carrier which contains a wafer in a stocker; measuring
the environmental condition within the wafer carrier or around the
wafer carrier using the metrology tool positioned on the wafer
carrier during a storage of the wafer carrier; and transmitting a
data associated with the environmental condition to a fault
detection and classification system via an interface device that is
positioned at the stocker.
8. The method as claimed in claim 1, further comprising: placing
the wafer carrier on a shelf of a stocker; measuring a leveling
degree of the shelf; and indicating an abnormality of the stocker
when the leveling degree is greater than a preset angle.
9. The method as claimed in claim 1, wherein the environmental
condition comprises at least one of temperature, humidity, air
pressure, a level of particle concentration, a level of gas
concentration, or a level of metal ion concentration.
10. A method for processing a wafer, comprising: forming a material
layer over a wafer in a first processing tool; loading the wafer
formed with the material layer into a wafer carrier; moving the
wafer carrier containing the wafer from the first processing tool
to a second processing tool and monitoring an environmental
condition within the wafer carrier, wherein the movement of the
wafer carrier containing the wafer from the first processing tool
to the second processing tool is executed multiple times; storing
data associated with the environmental condition in an archive
database in the previous movement of the wafer carrier; and
stopping the movement of the wafer carrier from the first
processing tool to the second processing tool and transferring the
wafer carrier to a rework station for removing the material layer,
when the environmental condition monitored by a metrology tool is
outside a range of acceptable values, wherein the range of
acceptable values is derived from the archive database.
11. The method as claimed in claim 10, wherein the range of
acceptable values is determined by a component of the material
layer.
12. The method as claimed in claim 10, wherein the wafer carrier is
moved by a transportation apparatus, and the method further
comprises: transmitting a data associated with the environmental
condition to a fault detection and classification system via an
interface device that is positioned at the transportation
apparatus.
13. The method as claimed in claim 10, further comprising: placing
the wafer carrier on a load port of the first processing tool; and
transmitting a data associated with the environmental condition to
a fault detection and classification system via an interface device
that is positioned at the load port.
14. The method as claimed in claim 10, further comprising: placing
the wafer carrier on a load port of the first processing tool;
measuring a leveling degree of the load port; and indicating an
abnormality of the load port when the leaving degree is outside an
acceptable range.
15. The method as claimed in claim 10, wherein the environmental
condition comprises temperature, humidity, air pressure, a level of
particle concentration, a level of gas concentration, and a level
of metal ion concentration.
16. A fabrication facility, comprising: a wafer carrier configured
to receive at least one wafer; a processing tool having a load port
configured to dock the wafer carrier; a transportation apparatus
configured to move the wafer carrier to the load port, wherein the
transportation apparatus includes a trail assembly and an overhead
hoist transport assembly movably suspend on the trail assembly; a
metrology tool positioned on the wafer carrier, wherein the
metrology tool includes at least one sensor configured to: measure
an environmental condition within the wafer carrier or in a
vicinity of the wafer carrier; and measure a leveling degree of the
load port when the wafer carrier is placed on the load port of the
processing tool; and an interface device positioned in the
transportation apparatus, wherein the interface device includes a
power circuit configured to supply power to the metrology tool.
17. The fabrication facility as claimed in claim 16, wherein the
interface device further includes an antenna configured to transmit
a data associated with the environmental condition from the
metrology tool to a fault detection and classification system for
analysis.
18. The fabrication facility as claimed in claim 16, wherein the
metrology tool is positioned on an inner surface or an outer
surface of the wafer carrier.
19. The fabrication facility as claimed in claim 16, further
comprising a stocker configured for storage of the wafer carrier,
wherein the transportation apparatus is configured to move the
wafer carrier between the load port of the processing tool and a
load port of the stocker, wherein the metrology tool is further
configured to measure a leveling degree of the load port of the
stocker when the wafer carrier is placed on the load port of the
stocker.
20. The fabrication facility as claimed in claim 16, wherein the
environmental condition comprises temperature, humidity, air
pressure, a level of particle concentration, a level of gas
concentration, and a level of metal ion concentration.
Description
BACKGROUND
The semiconductor integrated circuit (IC) industry has experienced
exponential growth. Technological advances in IC materials and
design have produced generations of ICs where each generation has
smaller and more complex circuits than the previous generation. In
the course of IC evolution, functional density (i.e., the number of
interconnected devices per chip area) has generally increased while
geometric size (i.e., the smallest component (or line) that can be
created using a fabrication process) has decreased. This
scaling-down process generally provides benefits by increasing
production efficiency and lowering associated costs. Such
scaling-down has also increased the complexity of processing and
manufacturing ICs.
ICs are typically fabricated by processing one or more wafers as a
"lot" with using a series of wafer fabrication tools (i.e.,
"processing tools"). Each processing tool typically performs a
single wafer fabrication process on the wafers in a given lot. For
example, a particular processing tool may perform layering,
patterning and doping operations or thermal treatment. A layering
operation typically adds a layer of a desired material to an
exposed wafer surface. A patterning operation typically removes
selected portions of one or more layers formed by layering. A
doping operation typically incorporates dopants directly into the
silicon through the wafer surface, to produce p-n junctions. A
thermal treatment typically heats a wafer to achieve specific
results (e.g., dopant drive-in or annealing). As a result, there is
a need for transporting the wafer in the factory.
Although numerous improvements to the methods of transporting wafer
have been invented, they have not been entirely satisfactory in all
respects. Consequently, it would be desirable to provide a solution
to improve the transportation system so as to mitigate or avoid the
production of excess scrap wafer due to improper storage conditions
for the wafer during its transportation.
BRIEF DESCRIPTION OF THE DRAWINGS
Aspects of the present disclosure are best understood from the
following detailed description when read with the accompanying
figures. It should be noted that, in accordance with the standard
practice in the industry, various features are not drawn to scale.
In fact, the dimensions of the various features may be arbitrarily
increased or reduced for clarity of discussion.
FIG. 1 is a block diagram of a fabrication facility, in accordance
with some embodiments.
FIG. 2 is a schematic view of partial elements of the fabrication
facility, in accordance with some embodiments.
FIG. 3 is a schematic view of a wafer carrier, in accordance with
some embodiments.
FIG. 4 is a block diagram of partial elements of the fabrication
facility, in accordance with some embodiments.
FIG. 5 is a flowchart of a method of enabling fault detection in a
wafer carrier, in accordance with some embodiments.
FIG. 6 is a diagram plotting measured humidity in a wafer carrier
versus time of storing a wafer in the wafer carrier, upper control
limits and lower control limits, in accordance with some
embodiments.
FIG. 7 is a flowchart of a method of enabling fault detection
around a wafer carrier, in accordance with some embodiments.
FIG. 8A is a diagram plotting expected humidity in a fabrication
system versus locations, in accordance with some embodiments.
FIG. 8B is a diagram plotting humidity measurement in a fabrication
system versus locations, in accordance with some embodiments.
FIG. 9 is a flowchart of a method of enabling fault detection in a
stocker, in accordance with some embodiments.
FIG. 10 is a schematic view of a shelf of a stocker in an abnormal
condition, in accordance with some embodiments.
DETAILED DESCRIPTION
The following disclosure provides many different embodiments, or
examples, for implementing different features of the subject matter
provided. Specific examples of solutions and arrangements are
described below to simplify the present disclosure. These are, of
course, merely examples and are not intended to be limiting. For
example, the formation of a first feature over or on a second
feature in the description that follows may include embodiments in
which the first and second features are formed in direct contact,
and may also include embodiments in which additional features may
be formed between the first and second features, such that the
first and second features may not be in direct contact. In
addition, the present disclosure may repeat reference numerals
and/or letters in the various examples. This repetition is for the
purpose of simplicity and clarity and does not in itself dictate a
relationship between the various embodiments and/or configurations
discussed.
Furthermore, spatially relative terms, such as "beneath," "below,"
"lower," "above," "upper" and the like, may be used herein for ease
of description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. The
spatially relative terms are intended to encompass different
orientations of the device in use or operation in addition to the
orientation depicted in the figures. The apparatus may be otherwise
oriented (rotated 90 degrees or at other orientations) and the
spatially relative descriptors used herein may likewise be
interpreted accordingly. It should be understood that additional
operations can be provided before, during, and after the method,
and some of the operations described can be replaced or eliminated
for other embodiments of the method.
FIG. 1 is a block diagram of a fabrication facility 1 according to
various aspects of the present disclosure. The fabrication facility
1 implements integrated circuit manufacturing processes to
fabricate integrated circuit devices. For example, the fabrication
facility 1 may implement semiconductor manufacturing processes that
fabricate semiconductor wafers. It should be noted that, in FIG. 1,
the fabrication facility 1 has been simplified for the sake of
clarity to better understand the inventive concepts of the present
disclosure. Additional features can be added in the fabrication
facility 1, and some of the features described below can be
replaced or eliminated in other embodiments of the fabrication
facility 1. The fabrication facility 1 may include more than one of
each of the entities in the depicted embodiment, and may further
include other entities not illustrated in the depicted
embodiment.
In some embodiments, the fabrication facility 1 includes a network
20 that enables various entities (a fabrication system 30, a
metrology system 40, a fault detection and classification (FDC)
system 50, a control system 60, an archive database 70, and another
entity 80) to communicate with one another. The network 20 may be a
single network or a variety of different networks, such as an
intranet, the Internet, another network, or a combination thereof.
The network 20 may include wired communication channels, wireless
communication channels, or a combination thereof.
FIG. 2 is a schematic view of partial elements of the fabrication
facility 1, in accordance with some embodiments. In some
embodiments, the fabrication system 30 includes a number of
processing tools, such as a first processing tool 31 and a second
processing tool 32, a stocker 33, a rework station 34, a number of
interface devices 35, and a transportation apparatus 36.
The first processing tool 31 and the second processing tool 32 are
configured to perform a wafer fabrication process. The first
processing tool 31 and the second processing tool 32 may include
any type of wafer processing tools used in semiconductor chip
fabrication. In some embodiments, the first processing tool 31 is a
deposition tool for forming a material layer over a wafer (not
shown in FIG. 2), and the second processing tool 32 is a
lithography tool for performing a lithography process over the
material layer formed on the wafer. Alternatively, the first
processing tool 31 and the second processing tool 32 may include
metrology, inspection, testing or other tool.
In some embodiments, the first processing tool 31 includes one or
more load ports 311, and the second processing tool 32 includes one
or more load ports 321. The load ports 311 and 321 are configured
to support and dock the wafer carriers 10 for facilitating the
insertion of wafer carriers 10 into, and their subsequent removal
from, processing chambers 312 and 322 of the first processing tool
31 and the second processing tool 32.
The stocker 33 is configured to automation storage and retrieval of
the wafer carrier 10. In some embodiments, the stocker 33 includes
a main body 330, a number of storage shelves 331 and a number of
load ports 332. In some embodiments, the main body 330 is a
rectangular enclosure. The storage shelves 331 are positioned
inside the main body 330 and configured to facilitate the storage
of the wafer carriers 10 within the main body 330. The wafer
carrier 10 may be transferred by a robotic arm (not shown in
figures), and the transportation or the movement of the wafer
carrier 10 in the stocker 33 is controlled by the control system
60. The load port 332 is configured to support and dock the wafer
carriers 10 for facilitating the insertion of wafer carriers 10
into, and their subsequent removal from, the main body 330 of the
stocker 33. The load port 332 is positioned along the trail
assembly 361 of the transportation apparatus 36 so as to receive
the wafer carriers 10 transferred from the vehicle of the
transportation apparatus 36.
The rework station 34 is configured to perform a rework process to
the wafer (not shown in FIG. 2) which has been processed by the
first processing tool 31 or the second processing tool 32. In some
embodiments, the rework station 34 includes a cleaning tool. The
wafer in the rework station 34 may be cleaned with a cleaning
liquid, and a material layer, such as photo resistor, is removed
from the wafer. In some other embodiments, the rework station 34
includes an etching tool. The wafer in the rework station 34 may
undergo plasma, and a material layer, such as metal layer, is
removed from the wafer. In some embodiments, the rework station 34
includes one or more load ports 341 configured to support and dock
the wafer carriers 10 for facilitating the insertion of wafer
carriers 10 into, and their subsequent removal from, the processing
chamber 342 of the rework station 34.
The transportation apparatus 36 is configured to transport or
convey the wafer carrier 10 to and from different locations in the
fabrication system 30. The transportation apparatus 36 includes a
trail assembly 361 and a number of overhead hoist transport (OHT)
assemblies 362, in accordance with some embodiments. The trail
assembly 361 is mounted on the ceiling of a FAB, for example. The
OHT assembly 362 is suspended by the trail assembly 361, and the
transportation or the movement of the OHT assembly 362 on the trail
assembly 361 is controlled by the control system 60. The OHT
assembly 362 is operable to raise and lower the wafer carriers,
thereby allowing the wafer carriers 10 from the load ports 311,
321, 332, and 341 positioned along and on the floor beneath the
trail assembly 361.
The interface devices 35 are positioned in multiple positions of
the fabrication system 30 where the wafer carrier 10 may be placed.
For example, each of the load ports 311 of the first processing
tool 31 has an interface device 35 mounted inside. In addition,
each of the load ports 332 and each of the shelves 331 of the
stocker 33 has an interface device 35 mounted inside. Moreover,
each of the OHT assemblies 362 has an interface device 35 mounted
inside. Elements of the interface device 35 will be described in
more detail later with reference to FIG. 5.
FIG. 3 shows a schematic view of a wafer carrier 10, in accordance
with some embodiments. The wafer carrier 10 is configured to
transport a number of semiconductor wafers, e.g., 6 wafers, 12
wafers, 24 wafers, etc. The wafer carrier 10 may be standard
mechanical interfaces (SMIFs) for loading semiconductor wafers each
having a diameter of 200 mm. Alternatively the wafer carrier 10 may
be front opening unified pods (FOUPs), which may be used to load
300 mm or 450 mm semiconductor wafers, or semiconductor wafers with
larger diameters. Other types and/or sizes of wafer carrier or pod
are, however, not excluded.
In some embodiments, each of the wafer carriers 10 includes a
housing 11 for containing a number of wafers 5 (only one wafer 5 is
shown in FIG. 3). The housing 11 includes a container 12 and a door
17, in accordance with some embodiments. The container 12 may be
opened when the door 17 is disengaged from the container 12.
Alternatively, the container 12 may be closed when the door 17 is
engaged with the container 12.
The container 12 has an upper wall 121, a lower wall 122, and a
side wall unit 123. The upper wall 121 is opposite to the lower
wall 122. The side wall unit 123 includes a numbers of panels
connected between the upper wall 121 and the lower wall 122. In
some embodiments, the side wall unit 123 includes three panels
1231, 1233, and 1235. The three panels 1231, 1233, and 1235 are
consecutively connected between the upper wall 121 and the lower
wall 122.
The door 17 is selectively engaged with the container 12. When the
door 17 is engaged with the container 12, the door 17 is held by
the upper wall 121 and the lower wall 122, and the panels 1231 and
1235, cooperatively. As a result, an enclosure 110 of the wafer
carrier 10 is formed inside of the housing 11. The wafers 5 are
loaded into an enclosure 110 of the wafer carrier 10 or unloaded
from the enclosure 110 of the wafer carrier 10 when the door 17 is
disengaged from the container 12.
In some embodiments, each of the wafer carriers 10 further includes
multiple supporting members 124 for supporting the semiconductor
wafers 120. The supporting members 124 are located inside of the
enclosure 110, and the supporting members 124 are fixed at the side
wall unit 123 of the container 12. In some embodiments, the
supporting members 124 respectively extend along a direction
parallel to the upper wall 121 and the lower wall 122. Therefore,
the wafers 5 supported by the supporting members 124 are parallel
to the upper wall 121 and the lower wall 122.
In some embodiments, each of the wafer carriers 10 further includes
a plate member 125. The plate member 125 is disposed on the upper
wall 121 of the housing 11. The plate member 125 is configured for
being gripped by a gripper (not shown) of the OHT assembly 362
(FIG. 2).
The metrology system 40 is configured to detect one or more
environmental conditions in the wafer carrier 10 or detect one or
more environmental conditions around the wafer carrier 10 and/or
detect a leveling degree of the wafer carrier 10. Examples of the
detected environmental conditions include temperature, humidity,
air pressure, the level of particle concentration, the level of gas
concentration, and/or the level of metal ion concentration.
In some embodiments, the metrology system 40 includes a number of
metrology tools 40a, 40b and 40c. The metrology tool 40a is
positioned on an inner surface 1211 of the upper wall 121 and is
configured to detect environmental conditions in the enclosure 110
of the wafer carrier 10. The metrology tool 40b is positioned on an
outer surface 123O of the side wall unit 123 (such as outer surface
of the panel 1235) and is configured to detect environmental
conditions around the wafer carrier 10. The metrology tool 40c is
positioned on an outer surface 121O of the upper wall 121 and is
configured to detect environmental conditions around the wafer
carrier 10 and/or a leveling degree of the wafer carrier 10. It
should be appreciated that the number and the location of the
metrology tools 40a, 40b and 40c should not be limited to the
embodiment shown in FIG. 3 and can be varied according to
demands.
FIG. 4 shows a block diagram of partial elements of the fabrication
facility 1, in accordance with some embodiments. While the
embodiments of FIG. 4 use the metrology tool 40a as an example, the
metrology tool 40b and 40c can be configured to have a
configuration that is the same or similar.
In some embodiments, the metrology tool 40a includes one or more
sensors, such as sensors 41 and 42. Each of the sensors 41 and 42
is configured to detect one of the environmental conditions. The
multiple sensors 41 and 42 allow different types of data associated
with environmental conditions to be collected simultaneously.
Alternatively, each of the sensors 41 and 42 is configured to
detect more than one of the environmental conditions in the wafer
carrier 10. In some embodiments, the metrology tool 40a further
includes a leveling sensor 43. The leveling sensor 43 is configured
to detect a leveling degree of the wafer carrier 10.
In some embodiments, the metrology tool 40a also includes a signal
converter 44, a processor 45, a storage device 46 and an input and
output (I/O) controller 47. The signal converter 44 receives the
output of the sensors 41, 42 and 43 as input. The signal converter
44 includes a multi-channel analog-to-digital converter in the
present embodiment, and each channel is capable of converting the
analog signal output from one of the sensors 41, 42 and 43 into
digital form. In alternative embodiments where the sensors 41, 42
and 43 output digital signals, the signal converter 44 may perform
the necessary data processing on the digital signal outputs of the
sensors 41, 42 and 43.
The signal converter 44 then outputs the data associated with
environmental conditions to an input of the processor 45, which
performs further processing on the data. In an embodiment, the
processor 45 controls the operations of the signal converter 44 and
the I/O controller 47. In yet another embodiment, the signal
converter 44 is integrated into the processor 45.
The processor 45 can communicate with the storage device 46. For
example, data associated with environmental conditions can be
transferred between the storage device 46 and the processor 45 to
enhance the functionality of the processor 45. The storage device
46 may be any form of memory, including Flash, Memory Stick,
Micro-SD, or a hard disk. In yet another alternative embodiment,
the storage device 46 may be integrated into the processor 45. In
some embodiments, the storage device 46 is separated from the
metrology tool 40a and is independently positioned on the plate
member 125 for easily access the information by the interface
device 35 positioned in the OHT assemblies 362.
The I/O controller 47 is operatively coupled to the processor 45.
The I/O controller 47 may be integrated with the processor 45 or it
may be a separate component as shown. The I/O controller 47 is
generally configured to control interactions with one or more
interface devices 35 that can be coupled to the wafer carrier 10.
The I/O controller 47 generally operates by exchanging data between
the metrology tool 40a and the interface devices 35 that desire to
communicate with the metrology tool 40a. In some cases, the
interface devices 35 may be connected to the I/O controller 47
through wired connections and in other cases the interface devices
35 may be connected to the I/O controller 47 through wireless
connections, such as WIFI, 3G, 4G, LTE, 5G, or bluetooth.
In the illustrated embodiment, the interface device 35 is capable
of being connected to the I/O controller 47 through a wired
connection. In this case, the wafer carrier 10 includes a data
connector 13 coupled to the I/O controller 47. The data connector
13 is capable of connecting to a corresponding a data connector 353
and a transceiver 351 located within the interface device 35, and
the data connector 13 is configured to engage the data connector
353 so as to provide data transmissions to and from the metrology
tool 40a.
The wafer carrier 10 also includes a power connector 14. The power
connector 14 of the wafer carrier 10 is operatively coupled to a
battery 15 of the wafer carrier 10. The power connector 14 is
configured to engage a power connector 354 and a power circuit 355
of the interface device 35 so as to provide operational or charging
power to the battery 15. The battery 15 may be positioned on the
outer surface 121O of the upper wall 121, as shown in FIG. 3 and
supply power to the metrology tool 40a. The data connectors 13/353
and the power connectors 14/354 may vary widely. For example, they
may be configured to provide one or more data (or power)
transmitting functions including USB, USB 2.0, Ethernet, and the
like.
In some embodiments, the interface device 35 further includes a
processor 352, a transceiver 357, and a code reader 356. In
addition, the wafer carrier 10 further includes a carrier
identification 16, such as a RFID tag. The carrier identification
16 wirelessly transmits signals with various information on the
wafer carrier 10 to the code reader 356, including, but not limited
to, the identity of the wafer 5 contained in the wafer carrier
10.
The code reader 356 then outputs the data of the wafer carrier 10
to an input of the processor 352. The processor 352 performs
further processing on the data from the code reader 356 and the
transceiver 351 and outputs the processed data to the transceiver
357 for data transmission to the FDC system 50 or the control
system 60 via an antenna 358. For example, the processor 352
matches the carrier identity from the carrier identification 16
with the metrology data from the metrology system 40, so that the
FDC system 50 can reorganize the metrology data is sent from which
wafer carrier 10. Therefore, the information of the wafer carrier
10 including the environmental conditions within the wafer carrier
10 can be processed by the FDC system 50 or the control system
60.
Back to FIG. 1 again, the FDC system 50 evaluates conditions in the
wafer carrier 10 to detect abnormalities or faults, such as
humidity change in the wafer carrier 10, by monitoring the data
associated the environmental conditions in the wafer carrier 10
before, during, and after the transportation process. In one
example, an abnormality is indicated when the level of gas
concentration of the wafer carrier 10 varies (higher or lower)
significantly from the expected level of gas concentration
determined, for example, by archival data stored in the archive
database 70 or archival data transmitted from the carrier
identification 16. Such abnormalities may indicate that there is a
fault with the wafer 5. For example, damage to the wafer carrier 10
may cause the gas concentration within the wafer carrier 10 to vary
from the expected gas concentration.
The FDC system 50 also evaluates conditions around the wafer
carrier 10 to detect abnormalities or faults, such as humidity
change in the vicinity of the wafer carrier 10, by monitoring the
data associated the environmental conditions around the wafer
carrier 10 before, during, and after the transportation process. In
one example, an abnormality is indicated when the humidity around
the wafer carrier 10 varies (higher or lower) significantly from
the expected humidity determined, for example, by archival data
stored in the archive database 70 or archival data transmitted from
the carrier identification 16. Such abnormalities may indicate that
there is a fault with the first and second processing tools 31 and
32. For example, a leakage of chemical solution outside of the
first and second processing tools 31 and 32 may cause the humidity
of the fabrication system 30 to vary from the expected
humidity.
In some embodiments, the FDC system 50 implements statistical
process control (SPC) to track and analyze the condition of the
wafer carrier 10. For example, the FDC system 50 may implement SPC
charts that document historical data of the wafer carrier 10 by
charting SPC data associated with the process over time. Such SPC
data includes parameters associated with the location of the wafer
carrier 10. When the SPC data indicates that parameters have
departed from a range of acceptable values (in other words, when
the FDC system 50 detects a fault or abnormality), the FDC system
50 triggers a warning to the control system 60 and/or notifies an
engineer or operator of the fabrication system 30, so that any
fault with the wafer carrier 10 may be identified and remedied.
The control system 60 can implement control actions in real time,
wafer-to-wafer, lot-to-lot, or a combination thereof. In the
depicted embodiments, the control system 60 implements control
actions to control the operation status of the fabrication system
30. For example, the control system 60 (based on a warning from the
FDC system 50) shuts down the operation of the first processing
tool 31 so as to stop the process being performed in the first
processing tool 31. In some other embodiments, the control system
60 implements control actions to actuate the transportation
apparatus 36 to move the wafer carrier 10 to the rework station 34
to remove a material layer formed on the wafer 5.
In some other embodiments, the control system 60 implements control
actions to modify process parameter performed by the first
processing tool 31 and/or the second processing tool 32. For
example, the control system 60 (based on inline metrology data from
the metrology system 40) modifies the predetermined process
parameter (specifically, the parameters implemented by the first
processing tool 31 and/or the second processing tool 32, such as
process time, flow rate of gas, chamber pressure, chamber
temperature, wafer temperature, or other process parameters) for
each wafer to ensure that each wafer located in the first
processing tool 31 and/or the second processing tool 32 exhibits
the targeted characteristics.
The archive database 70 may include a number of storage devices to
provide information storage. The information may include raw data
obtained directly from the metrology system 40, as well as
information from the fabrication system 30. For example, the
information from the metrology system 40 may be transferred to the
archive database 70 and stored in the archive database 70 for
archival purposes. The data from the metrology system 40 may be
stored in its original form (e.g., as it was obtained from the
metrology system 40 or the fabrication system 30) and it may be
stored in its processed form (e.g., converted to a digital signal
from an analog signal). The archive database 70 stores data
associated with the fabrication facility 1, and particularly data
associated with the environmental conditions in the wafer carrier
10 and around the wafer carrier 10.
In the depicted embodiment, the archive database 70 stores data
collected from the fabrication system 30, the metrology system 40,
the FDC system 50, the control system 60, another entity 80, or a
combination thereof. For example, the archive database 70 stores
data associated with wafer characteristics of wafers processed by
the fabrication system 30 (such as that collected by the metrology
system 40 as described below), data associated with parameters
implemented by the fabrication system 30 to process such wafers,
data associated with analysis of the wafer characteristics and/or
parameters of the FDC system 50 and the control system 60, and
other data associated with the fabrication facility 1. In one
example, the fabrication system 30, the metrology system 40, the
FDC system 50, the control system 60, and the other entity 80 may
each have an associated database.
FIG. 5 is a simplified flowchart of a method S10 of enabling fault
detection within the wafer carrier 10, in accordance with some
embodiments. For illustration, the flow chart will be described
along with the drawings shown in FIGS. 1-4. Some of the described
stages can be replaced or eliminated in different embodiments.
The method S10 includes operation S11, in which data associated
with the expected environmental conditions in the wafer carrier 10
containing one or more wafers 5 is collected. The data associated
with the expected environmental conditions in the wafer carrier 10
may be in the form of a range of values within which it has been
observed that normal conditions in the wafer carrier 10
consistently occur.
In some embodiments, the data is retrieved from the archive
database 70 and sent to the FDC system 50. In some other
embodiments, the data is collected by the interface device 35 which
transmits the data read from the carrier identification 16 to the
FDC system 50. In some other embodiments, the data is applied to
the FDC system 50 by engineering or processing knowledge.
In some embodiments, the data associated with the expected
environmental conditions in the wafer carrier 10 is determined by a
component of the material layer formed on the wafer 5. For example,
the material layer formed on the wafer 5 includes a metal layer.
While the wafer 5 is stored in the wafer carrier 10, the level of
gas concentration (such as oxygen concentration) is expected to
stay within a range of values so as to make sure the condition of
the metal layer is acceptable. Since different components of the
material layer require different storage conditions, the data
associated with the expected level of gas concentration may vary
according to the components of the material layer.
The method S10 also includes operation S12, in which the wafer
carrier 10 is transferred from an original position to a
destination position. In some embodiments, the wafer carrier 10 is
moved by the transportation apparatus 36 from the first processing
tool 31 to the second processing tool 32, after a material layer is
formed by the first processing tool 31 over the wafers 5 that are
contained in the wafer carrier 10. In some embodiments, the wafer
carrier 10 is moved by the transportation apparatus 36 between the
stocker 33 and the first processing tool 31. In some other
embodiments, the wafer carrier 10 is moved between the load port
332 of the stocker 33 and one of the shelves 331 of the stocker 33.
The movement of the wafer carrier may be controlled by the control
system 60.
The method S10 also includes operation S13, in which environmental
conditions in the wafer carrier 10 are measured by the metrology
system 40. In some embodiments, the environmental conditions in the
wafer carrier 10 are measured during the transfer of the wafer 5.
For example, the measurement of the environmental conditions in the
wafer carrier 10 is initiated once the wafer carrier 10 is removed
from the load port 311 of the first processing tool 31, and the
measurement of the environmental conditions in the wafer carrier 10
is terminated once the wafer carrier 10 is positioned on the load
port 321 of the second processing tool 32.
In some embodiments, the measurement of the environmental
conditions in the wafer carrier 10 is executed periodically when
the wafer carrier 10 is coupled to the interface devices 35 in the
fabrication system 30. For example, during the movement of the
wafer carrier 10 from the shelf 331 to the load port 332 of the
stocker 33, the metrology system 40 will not start monitoring the
environmental conditions in the wafer carrier 10 until the wafer
carrier 10 is placed on the load port 332. In addition, during the
stay of the wafer carrier 10 on the shelf 331, the measurement of
the environmental conditions in the wafer carrier 10 is executed
multiple times at regular time intervals. The detected data
associated with the environmental conditions in the wafer carrier
10 is transmitted in real time to the FDC system 50 via the
interface devices 35.
However, it should be appreciated that many variations and
modifications can be made to embodiments of the disclosure. The
measurement of the environmental conditions in the wafer carrier 10
may be executed continuously no matter whether the wafer carrier 10
is engaged with the interface devices 35 or not. The detected data
associated with the environmental conditions in the wafer carrier
10 is stored in the storage device 46 of the metrology system 40
and sent to the FDC system 50 when the wafer carrier 10 is coupled
to one of the interface devices 35. Alternatively, the detected
data associated with the environmental conditions in the wafer
carrier 10 is transmitted to the FDC system 50 in real time through
wireless connections.
In some embodiments, the measurement of the environmental
conditions in the wafer carrier 10 is executed even during the
removal of the wafer 5. For example, once the wafer carrier 10 is
placed on the load port 311 of the first processing tool 31, the
wafer 5 is removed from the wafer carrier 10 by a robot arm (not
shown in figures) and moved to an interface module in the first
processing tool 31. At this time, since the interior (such as the
enclosure 110) of the wafer carrier 10 communicates with the
interior of the first processing tool 31, the metrology system 40
can be used to detect environmental conditions in the first
processing tool 31.
The method S10 also includes operation S14, in which the data
associated with the measured environmental conditions produced in
operation S13 is compared with data associated with the expected
environmental conditions collected in operation S11. In some
embodiments, the measured environmental conditions obtained in
operation S13 is compiled in a time-series chart (T-chart) as shown
in FIG. 6, and the T-chart is analyzed by the FDC system 50.
In some embodiments, before analyzing the T-chart, a range of
acceptable values for the measured environmental conditions is
determined. The range of acceptable values for the measured
environmental conditions may be a standard deviation from an
expected value. For example, as shown in FIG. 6, an upper control
limit (UCL) is set at the expected oxygen concentration (EXP) plus
one standard deviation of the oxygen concentration, and lower
control limits (LCL) are set at the expected oxygen concentration
(EXP) minus one standard deviation of the oxygen concentration. The
difference between the UCL and LCL at a specific time is referred
to as the range of acceptable values. In some embodiments, the
range of acceptable values is determined by the material layer
formed on the wafers 5 that are stored in the wafer carrier 10.
Alternatively, the range of acceptable values for the measured
environmental conditions may be a specific ratio of the expected
environmental conditions in each process event. For example, UCL
are set at the expected level of oxygen concentration plus about 2%
of the level of oxygen concentration, and LCL are set at the
expected level of oxygen concentration minus about 2% of the level
of gas concentration. The difference between the UCL and LCL at a
specific time is referred to as the range of acceptable values.
After the range of acceptable values for the measured environmental
conditions is determined, the FDC system 50 analyzes the measured
environmental conditions to determine if the measured environmental
conditions are within the acceptable range.
After the analysis, if the measured environmental conditions are
within the range of acceptable values, the method repeats operation
S13 and S14 until the predetermined period for monitoring the wafer
carrier 10 is finished, for example, until the operation S12 is
finished. However, if the measured environmental conditions exceed
the range of acceptable values, the method continues with operation
S15, in which an alarm condition is indicated. For example, as
shown in FIG. 6, at time t1, the measured level of oxygen
concentration is higher than the UCL. Namely, the measured level of
oxygen concentration is outside the range of acceptable values, and
a warning is issued at time t1.
In some embodiments, when the data processed by the FDC system 50
indicates that the measured environmental conditions has departed
from the expected environmental conditions (in other words, when
the FDC system 50 detects a fault or abnormality), the FDC system
50 triggers an alarm. In some embodiments, out-of-specification
data indicates a fault (or abnormality) in the wafer carrier 10,
such as exposure of the wafer 5 to the outside of the wafer carrier
10 or a generation of outgassing in the wafer carrier 10.
The exposure of the wafer to the outside of the wafer carrier 10 or
generation of outgassing in the wafer carrier 10 may damage the
material layer formed on the wafer 5. If additional material layers
are formed on the damaged material layer, it will not only cause
excessive wafer scrap but also a waste of manufacturing resources.
To prevent this from happening, the FDC system 50 triggers an alarm
and notifies the control system 60 to move the wafer carrier 10
along with the wafer 5 to the rework station 34 (FIG. 2) for
removing the material layer, so that the wafer 5 can be sent to the
first processing tool 31 at which a new material layer is formed on
the wafer 5.
When the wafer 5 is processed in the rework station 34, any
suitable process may be performed on the wafer 5 so as to remove
the material layer formed on the wafer 5. For example, an etching
process is performed over the wafer 5, so as to remove the material
layer by plasma. Alternatively, a cleaning process is performed
over the wafer 5, so as to remove the material layer using a
cleaning liquid.
Afterwards, the wafer carrier 10 along with the wafer 5, which has
been reworked, are moved to the first processing tool 31 for
forming another new material layer, or to the stocker 33 for
storage. During the movement of the wafer 5, the environmental
conditions in the wafer carrier 10 are also detected using the
method S10 described above.
FIG. 7 is a simplified flowchart of a method S20 of enabling fault
detection around the wafer carrier 10, in accordance with some
embodiments. For illustration, the flow chart will be described
along with the drawings shown in FIGS. 2 and 8. Some of the
described stages can be replaced or eliminated in different
embodiments.
The method S20 includes operation S21, in which data associated
with the environment conditions around the wafer carrier 10 is
collected. In some embodiments, data associated with environment
conditions at selected locations in the fabrication system 30 is
produced by the metrology tool 40b and is sent to the archive
database 70.
In some embodiments, the data associated with environment
conditions is collected at selected locations while the wafer
carrier 10 is transported by the transportation apparatus 36 from
one location to another location in the fabrication facility 1.
Specifically, data associated with environment conditions is
measured at locations P10 and P20 (FIG. 2) where the first process
tool 31 and the second processing tool 32 are located. The
measurement may be respectively executed while the wafer carrier 10
is unloaded from the first process tool 31 and while the wafer
carrier 10 is loaded on the second processing tool 32.
Alternatively or additionally, the data associated with environment
conditions is measured multiple times during the transportation
from locations P10 to location P20 at regular time intervals, such
as every 0.5 seconds (2 points/sec), and the data associated with
environment conditions at each measured time interval are recorded
separately in the archive database 70. In this case, since the
location of the metrology tool 40b is changed with time, the
environment conditions correlated with location in the fabrication
system 30 is measured and recorded. The data is stored in the
archive database 70. One example for the data associated with one
of the environment conditions, such as humidity, in each location
is illustrated in table 1.1 below:
TABLE-US-00001 TABLE 1.1 No. EVENT NAME EVENT TIME HUMIDITY
LOCATION 1 (a) Lift carrier 00:00:00 15 P10 2 (b) Transfer 00:01:20
15 P20 3 (c) Transfer 00:01:40 15 P30 4 (d) Lower carrier 00:02:00
15 P40
The table 1.1 includes four columns, where the columns include a
data number column, an event name column, a humidity column and a
location column. The humidity column may record an amount of
moisture in the location where the metrology tool 40b is located.
The humidity column may record an amount of moisture at the event
time. The location column may record the location of the metrology
tool 40b in the fabrication facility 1.
The operation S21 may be repeated many times, as long as no fault
is found in the fabrication facility 1 (such as no chemical
leakage). Afterwards, data associated with the environment
conditions around the wafer carrier 10 detected at the selected
locations is stored in the archive database 70. The data may be
processed further before being stored in the archive database 70.
For example, the mean value of humidity measured at a specific
location of the last five measurements is calculated and stored in
the archive database 70. Additionally, the standard deviation of
humidity measured at a specific location of the last five
measurements is calculated and stored in the archive database 70.
As a result, a big data pattern is stored in the archive database
70.
However, it should be appreciated that many variations and
modifications can be made to embodiments of the disclosure. In some
embodiments, operation S21 is omitted. The values of humidity in
table 1.1 are applied into the archive database 70 by
engineering/process knowledge. For example, when it has been
observed that a normal condition in the fabrication facility 1
consistently occurs at a specific humidity, such humidity is
established as normal humidity and is applied into the archive
database 70.
The method S20 also includes operation S22, in which the wafer
carrier 10 is transferred from an original position to a
destination position. In some embodiments, the wafer carrier 10 is
moved by the transportation apparatus 36 from the first processing
tool 31 to the second processing tool 32, after a material layer is
formed by the first processing tool 31 over the wafers 5 that are
contained in the wafer carrier 10. In some embodiments, the wafer
carrier 10 is moved by the transportation apparatus 36 between the
stocker 33 and the first processing tool 31. In some other
embodiments, the wafer carrier 10 is moved between the load port
332 of the stocker 33 and one of the shelves 331 of the stocker 33.
The movement of the wafer carrier 10 may be controlled by the
control system 60.
The method S20 also includes operation S23, in which environmental
conditions around the wafer carrier 10 are measured by the
metrology tool 40b. In some embodiments, at least one of the
measurements in operation S23 corresponds to one of the
measurements in operation S21. For example, the measurements in
operation S23 occur at the same location with the measurements in
operation S21. In some embodiments, the number of measurements in
operation S23 is the same as the number of measurements in
operation S21. Alternatively, there are fewer measurements in
operation S23 than there are in operation S21.
The method S20 also includes operation S24, in which the
environmental conditions measured in operation S23 are compared
with an expected environmental conditions stored in the archive
database 70. In some embodiments, data associated with the expected
environmental conditions at different locations are derived from
archive database 70 to the FDC system 50. Since the data associated
with the expected environmental conditions from the archive
database 70 represent normal humidity of the fabrication facility
1, this data is also referred to as "expected environmental
conditions". While at the same time, the data associated with the
environmental conditions obtained in operation S23 is transmitted
from the metrology system 40 to the FDC system 50 via the interface
device 35.
In some embodiments, the data associated with the expected
environmental conditions is compiled in time-series chart (T-chart)
as shown in FIG. 8A, and the data associated with the measured
environmental conditions obtained in operation S23 is compiled in
time-series chart (T-chart) as shown in FIG. 8B.
In some embodiments, before analyzing the T-chart shown in FIG. 8B,
a range of acceptable values for the difference between the
expected environmental conditions measurement and the measured
environmental conditions at each selected location is determined.
The range of acceptable values for the difference may be a standard
deviation of the expected environmental conditions at each
location. For example, as shown in FIG. 8A, upper control limits
(UCL) are set at the expected humidity plus one standard deviation
of the expected humidity, and lower control limits (LCL) are set at
the expected humidity subtract one standard deviation of the
expected humidity. The difference between the UCL and LCL at a
specific time is referred to as the range of acceptable values.
Alternatively, the range of acceptable values for the difference
may be a specific ratio of the expected environmental conditions at
each selected location. For example, UCL are set at the expected
humidity plus about 2% of the expected humidity, and LCL are set at
the expected humidity subtract about 2% of the expected humidity.
The difference between the UCL and LCL at a specific time is
referred to as the range of acceptable values.
In some embodiments, the range of acceptable values for the
difference at two locations may be different. For example, as shown
in FIG. 8A, the range of acceptable values for the difference at
location P10 is smaller than the range of acceptable values for the
difference at location P30 because humidity at location P30 may be
changed by a variety of factors. However, it should be appreciated
that many variations and modifications can be made to embodiments
of the disclosure. The range of acceptable values for the
difference in all locations may be the same.
After the range of acceptable values for the difference between the
measured environmental conditions and the expected environmental
conditions is determined, the FDC system 50 compares the measured
environmental conditions at a selected location and the expected
environmental conditions corresponding to the same location to
determine if the difference there between is within the range of
acceptable values.
After the comparison, if the difference between the measured
environmental conditions and the expected environmental conditions
is within the range of acceptable value, the method repeats
operations S23 and S24. However, if the difference between the
measured environmental conditions and the expected environmental
conditions exceeds the range of acceptable values, the method
continues with operation S25, in which a warning is triggered.
In some embodiments, when the data processed by the FDC system 50
indicates that the measured environmental conditions have departed
from expected environmental conditions (in other words, when the
FDC system 50 detects a fault or abnormality), the FDC system 50
triggers an alarm. In some embodiments, out of specification data
exhibits behavior that indicates a fault (or abnormality) in the
fabrication system 30. In the present example, statistically
analyzed parameter data is out of specification when it exhibits
behavior associated with a chemical leak (such as gas or liquid) of
one of the processing tool that is positioned in the vicinity of
the wafer carrier 10.
It has been observed that leakage of a chemical, including liquid
solution, volatile gas, etc., will cause an increase in humidity in
the fabrication system 30. Therefore, to protect the fabrication
system 30 or the wafer 5 from damage, the FDC system 50 notifies an
operator and indicates the location where the fault has occurred so
that any issues with the fabrication system 30 may be identified
and remedied.
On the other hand, the FDC system 50 may optionally halt the
process performed by the first and second processing tools 31 and
32 located around the wafer carrier 10. For example, when the FDC
system 50 indicates that a fault has occurred at a location P11
between locations P10 and P20 where the first and second processing
tools 31 and 32 are situated, the FDC system 50 halts the process
performed by the first and second processing tools 31 and 32 to
prevent wafer scrap from happening in the first and second
processing tools 31 and 32.
FIG. 9 is a simplified flowchart of a method S30 of enabling fault
detection in the fabrication facility 1, in accordance with some
embodiments. For illustration, the flow chart will be described
along with the drawings shown in FIG. 10. Some of the described
stages can be replaced or eliminated in different embodiments.
The method S30 includes operation S31, in which the wafer carrier
10 is placed on the one of the shelves 331 of the stocker 33, as
shown in FIG. 10. The method S30 further includes operation S32, in
which a leveling degree of the one of the shelves 331 is measured
with the metrology tool 40c which includes a leveling sensor 43
(FIG. 4). For example, as shown in FIG. 10, the metrology tool 40c
measures the wafer carrier 10 which is placed on a plane M. The
plane M forms an angle .theta. relative to a horizontal plane H.
The angle .theta. is the leveling degree of the wafer carrier 10.
The method S30 also includes operation S33, in which the leveling
degree detected by the leveling sensor 43 is compared with a preset
value. The preset value may be in a range of about 2 degrees to
about 5 degrees.
Too large a leveling degree may indicate that one of the shelves
331 has been tilted. To prevent the wafer carrier 10 from being
dropped, the method S30 continues to operation S34, in which the
FDC system 50 triggers a warning and notifies the control system 60
to remove the wafer carrier 10 from one of the shelves 331, so that
damage to the wafer carrier 10 and the wafer 5 contained in the
wafer carrier 10 can be prevented.
Embodiments of method and device for fault detection in a
fabrication facility are provided. Data associated with the
environmental conditions in or around the wafer carrier are
detected and analyzed to determine whether an abnormal condition is
generated in the wafer carrier. When an abnormal situation occurs,
the control system will undertake an immediate response and handle
it properly. Therefore, damage to the fabrication tool for
processing semiconductor wafers can be mitigated or avoided and
wafer scarp is reduced.
In accordance with some embodiments, a method for fault detection
in a fabrication facility is provided. The method includes moving a
wafer carrier using a transferring apparatus. The method further
includes measuring an environmental condition within the wafer
carrier or around the wafer carrier using a metrology tool
positioned on the wafer carrier during the movement of the wafer
carrier. The method also includes issuing a warning when the
detected environmental condition is outside a range of acceptable
values.
In accordance with some embodiments, a method for processing a
wafer is provided. The method includes forming a material layer
over a wafer in a first processing tool. The method further
includes loading the wafer formed with the material layer into a
wafer carrier. The method also includes moving a wafer carrier
containing the wafer from the first processing tool to a second
processing tool and monitoring an environmental condition within
the wafer carrier. In addition, the method includes stopping the
movement of the wafer carrier from the first processing tool to the
second processing tool and transferring the wafer carrier to a
rework station for removing the material layer, when the
environmental condition measured by the metrology tool is outside a
range of acceptable values.
In accordance with some embodiments, a fabrication facility is
provided. The fabrication facility includes a wafer carrier
configured to receive at least one wafer. The fabrication facility
further includes a transferring apparatus configured to move the
wafer carrier. The fabrication facility also includes a metrology
tool positioned on the wafer carrier and configured to measure an
environmental condition within the wafer carrier or in the vicinity
of the wafer carrier. In addition, the fabrication facility
includes a control system. The control system is configured to
control an operation of the transferring apparatus to move the
wafer carrier to a rework station for removing a material layer
over the wafer when the environmental condition measured by the
metrology tool is outside a range of acceptable values.
Although the embodiments and their advantages have been described
in detail, it should be understood that various changes,
substitutions, and alterations can be made herein without departing
from the spirit and scope of the embodiments as defined by the
appended claims. Moreover, the scope of the present application is
not intended to be limited to the particular embodiments of the
process, machine, manufacture, composition of matter, means,
methods, and steps described in the specification. As one of
ordinary skill in the art will readily appreciate from the
disclosure, processes, machines, manufacture, compositions of
matter, means, methods, or steps, presently existing or later to be
developed, that perform substantially the same function or achieve
substantially the same result as the corresponding embodiments
described herein may be utilized according to the disclosure.
Accordingly, the appended claims are intended to include within
their scope such processes, machines, manufacture, compositions of
matter, means, methods, or steps. In addition, each claim
constitutes a separate embodiment, and the combination of various
claims and embodiments are within the scope of the disclosure.
* * * * *